rosco pretty well said it all. Here a list of tools needed to dismount the tires from the rim and re-mount back on the rim. If you aquire these, learn about airing up the wheels after you have remounted the tires on the wheels.
Picture #1 a slide hammer, a solid bar with handel that slides in and out of a larger tube with a duck-bill wedge at the bottom, used to break the tire bead from the wheel/rim
Picture #2 the same picture with a better view of it.
Picture #3 The typical truck tire wedge hammer. Picture 1, 2 and 3 are essentially the tool for bead breaking.
Picture #4 One of many brands available of tire goop, it has the consistancy of grease, but is a waxy soap, and is used to remount the tire back on the rim and facilitate an easy slide back on due to the slippery properties.
Picture #5 one of many configurations of truck tire bars, typically nearly waist heigth in length, also 'spoons' are used, again 2-3 foot long (for leverage) with a flat spoon shaped bussiness end.
Picture #6 is of EXTREME IMPORTANCE, the air chuck. You will see how it is made with a long lead and a clip-on chuck. This is so you can air from a distance and away from the wheel
I should add that it is imperative that you not stand over the wheel while airing, were the ring to seperate from the wheel, it becomes a MISSLE and will/can literly cut you in half (NO JOKE) It is best to have the CAGE pictured but barring that, Chains can be used, typically three at seperate locations, wraped aroung and bolted, NO WIMPY STUFF HERE + grade 8 bolts and hardened washers, somewhat in the shape of a triangle. Avoid having a chain next to the split in the ring, one must stand/kneel to the side as far as possable, low and away to the side, in case the ring does BLOW off. Take into acount also where the MISSLE'S path might be were it to cut loose. If you are inside.... it could blow a hole in your roof with a resulting 'rain' of debree falling down on you. I have personally seen the aftermath of one cutting loose because of improper seating of the ring and it went through two 2x12 rafters and 3/4" plywood roof with a neatly cut hole the size of the ring, I kid you NOT
Picture #7 is the said tire Cage. Were it to BLOW inside the cage it would in all likelyhood be contained, however I have seen destroyed cages, after one mishap.
I , as well as many other forum members framilliar with tire changing, advise extreme CAUTION and double-checking every step upon re-assembly. There are NO second chances with split rings.
I emphatically advise you that if you do not understand the method of dissasembly and assembly, or are unclear on any point, Then PLEASE, PLEASE do not attempt. One additional picture from a post by WillWagner shows how to chain the wheel in the absence of a cage